1. Field of the Invention
This invention relates to a two-piece closure for a blown plastic or glass container, the closure including a molded plastic inner plug style closure and a molded plastic collar which must be removed from the container before the molded plastic inner plug style closure can be removed, and which must be visibly and irreparably damaged during such removal to provide evidence of a prior opening or attempted opening of the container as as indication of any tampering with the container or its contents.
2. Description of the Prior Art
Molded plastic plug style closures are widely used as closures for bottles for the packaging of various dry, comestible products, for example, vitamin tablets, and are especially popular for packaging applications of this type which utilize blown plastic bottles as the container elements thereof, because of the similarity in the manufacturing tolerances which apply to the molded plastic plug style closures, on the one hand, and to the corresponding blown plastic bottles, on the other hand. However, such molded plastic plug style closures, each of which sealingly engages the bottle in which it is placed on the inside surface of the bottle neck, are not inherently tamper indicating upon the first removal of the closure from the bottle, and wherever it is desired to provide a bottle which is closed with a molded plastic plug style closure with tamper indicating opening characteristics, it is necessary to provide a separate element such as a tape or an overcap which must be torn away or otherwise irreparably damaged before the plug style closure can be removed from the bottle. For example, U.S. Pat. No. 3,924,771 (G. Cleff) discloses a heat shrinkable plastic foil outer cap which is placed over the neck portion of a bottle that is capped by a separate plug style or other closure. U.S. Pat. No. 4,271,972 (D. L. Thor) discloses a molded plastic overcap for a container which is closed by a plug closure, but the overcap of this reference is hinged, and, consequently, requires a complex latch type locking means to ensure that the integrity of the overcap is destroyed upon its first removal, as is required for proper tamper indicating performance characteristics. U.S. Pat. No. 3,952,901 (V. N. Conti) discloses a molded plastic closure retaining collar with a vertically extending tear strip to impart tamper indicating characteristics to such closure, but the closure of the container of this reference is an helically threaded closure, and it would appear that such a closure could be unscrewed from the associated container by a firm gripping and turning force applied to the exterior of the molded plastic overcap, a type of motion which would not result in the removal of a plug style closure from the container. U.S. Pat. No. 3,966,082 (B. D. Hopkins) discloses a package which is made up of a can, a plug style closure for an end of the can, and a molded plastic collar or overcap that secures the closure to the body of the can. However, the overcap of the package of this reference can be removed without irreparably damaging it, and, consequently, the package of this reference does not have tamper indicating opening characteristics.